The Global Database of Events, Language, and Tone (GDELT) is what happens when big data meets human history. Developed by Kalev Leetaru, a Yahoo Fellow in Residence at Georgetown University, it is a compendium of more than 250 million events spanning over three decades, and it’s causing a lot of excitement in academic and foreign policy circles. Researchers hope it could help track how events unfold, and even predict things going forward (Leetaru says he could have narrowed down where Osama Bin Laden was hiding, if anyone had asked him).

This visualization is based on one aspect of Leetaru’s database: popular protests. It shows every uprising in the world since 1979–from the Iranian Revolution, through the fall of the Berlin Wall, to the Arab Spring. Have a play and see what you can identify. It was created by John Beieler, a doctoral candidate at Penn State, and it’s a pretty stunning portrayal of a world in unending upheaval. Here’s a zoom in of recent protests in Egypt, for instance:

As J Dana Stuster writes at Foreignpolicy.com, the data has limitations. It shows only those events reported in the mainstream media, so if the New York Times skipped it, it effectively didn’t happen. Second, some events aren’t precisely geolocated, so are attributed to the middle of countries rather than towns or cities (hence all the action in Kansas).

Still, the strength of the map is to show connections between events: for example, how the revolutions in Eastern Europe spread in 1989 and 1990. Beieler tells Stuster: “To me, the most powerful part of these visualizations is being able to see the spatial patterns in unrest.”